The present invention relates to modular conveyor chains, and more particularly to a side guard for use on a modular conveyor chain link.
Modular belting is formed from interconnected links which are supported by a frame and driven to transport a product. Each link has a support surface which supports the product as the belting is being driven along the frame. In certain applications, side guards are fixed to, or are formed as an integral part of, the link to prevent a conveyed load from falling off of the belt. Side guards attached to the belt move with the product being conveyed to minimize relative motion between the support surface and the side guard. Minimizing the relative motion reduces product damage.
Prior art side guards, such as shown in FIGS. 1-4, are fixed to a modular belt, and are arranged in overlapping relation to prevent large longitudinal gaps from forming when the belt flexes around a drive or idle sprocket. The side guards are typically attached to the belt near the belt width edges, and are fixed at an angle, known as a shingle angle, relative to the belt edge to avoid interference between adjacent side guards.
The height of the side guard and amount of belt flexing required determines the extent of side guard overlap. As height or flexing requirements increase, more overlap is required to prevent gaps from opening up as the belt flexes. Increasing the overlap, typically requires a greater shingle angle to prevent interference between the side guards as the belt flexes.
Increasing the shingle angle to prevent interference between the side guards increases the clearance between adjacent side guards. When conveying small products, increasing overlap, and thus the shingle angle, between side guards is undesirable because the product can wedge between the side guards causing damage to the side guards and the product. Moreover, increasing the shingle angle causes the side guards to consume more of the belt area, thus reducing the usable area of the belt. Accordingly, a need exists for a belt having a side guard which can negotiate small sprockets without requiring a large shingle clearance.